I’d just turned 16 and went to Liverpool with a couple of Tottenham Hotspur-supporting mates for a game in 1978. There was no room in the away end, so we sneaked into the Kop. They weren’t too impressed — Spurs lost 7-0. But I was awestruck. The buzz from start to finish is something I’ll never forget. So often in life things don’t live up to your expectations, but the Anfield roar was everything I’d hoped for and more.

It’s not like that for every game these days, but next week it will be at its best. The supporters have a reputation to live up to. There’s no better atmosphere in England than Anfield on a European night. It’s not just noisy, it’s uplifting. It has volume and it has soul.

Liverpool’s players are lucky they will have that twelfth man because after Wednesday’s result they probably need it. “Inspired by the crowd”. It’s a common phrase. What does it actually mean to players? As often as not, replacing doubt with belief. Players will never say so in public, but on occasion they question themselves: can we really turn it around? Are we really good enough to beat this lot?

Constant, fierce support from the crowd makes them think it’s possible. I experienced it a few times. Once, with Millwall, we got a corner. I looked into the stands. His face pressed through a fence, a fan shouted at me: “We can f**king do it!” It changed my mentality. “Bloody hell,” I thought. “If he thinks we can, why shouldn’t I?” And we proved him right.

Imagine the power of thousands of people with the same attitude as that guy. Imagine what it’s like to be standing in the middle of the pitch surrounded by four walls of sound.

Then blend in the sense of history that is so strong at Anfield — the glories of past European nights that echo through the stadium. Tales of great results that are passed down through generations, so the kids on the Kop are part of the folklore like the dads and grandads who were there against Inter Milan in 1965. And it’s a visual experience too, so add a splash of colour — the scarves, banners and flags. Players can’t help but watch and wonder.

Stamford Bridge is hardly renowned for its atmosphere but it was rocking for the first leg. There’s something special in the air at night games. Fans feel it and so do the players. Evening matches somehow have added drama that Saturday afternoon games can’t equal.

I was in the Shed End. There was a flag on every seat, so before kick off the stands were oceans of blue. Everyone was waving theirs — except me. It’s not really my style. Then one fan gave me a rollocking for not getting involved.

Brilliant: more than a dozen years after my ill-fated stint as a Chelsea player and I’m still getting stick from the Shed. So I picked up the flag and waved it a bit self-consciously, probably looking like some kind of awkward Alan Partridge character in my suit. But that’s what the big nights can do. They are raw, they sweep you up, get you involved.

However sensible you are, you can’t help but be affected by the intensity of the emotion — and the desperation, because in a cup game there could be no tomorrow.

The fans pump up the players, they respond and everything snowballs. The stadium whips itself into a frenzy, opponents panic and crazy results such as Istanbul in 2005 become achievable.

Word of warning: Chelsea are not going to crumble in front of the Kop. Though some players are intimidated by hostile atmospheres, others relish them. I thought of it as a kind of test, a way of proving to myself and everyone else that I wasn’t a bottler.

Chelsea’s squad have amazing mental strength. They know that the sole tactic to combat the crowd is to quieten them. Far easier said than done, of course — probably only going 2-0 up on the night will do it.

Chelsea cannot control the referee’s reaction, though. With fans screaming for free kicks at even the sniff of a challenge, the potential effect of the crowd on the officials will be a bigger worry for Chelsea than the effect on their players. Good job José Mourinho’s not paranoid about referees, then.

Back from brink

Liverpool have overturned nine of the 22 first-leg deficits they have faced in European competition. Their most famous recoveries, having been behind at the end of the first leg, include beating St Etienne 3-1 at Anfield after losing 1-0 away in the European Cup quarter-finals in 1976-77 and, in the semi-finals of the same competition the next season, losing 2-1 away to Borussia Mönchengladbach but defeating the German side 3-0 in the second leg